Access traffic steering, switching, splitting (ATSSS) between access paths

Abstract

User plane function (UPF) receives 502, from a session management function (SMF), rules associated with a packet forwarding control protocol (PFCP) session of a multi-access protocol data unit (MA-PDU) session in which a 5G core (5GC) access path connects a first access of user equipment (UE) to the UPF via a 5GC and an evolved packet core (EPC) access path connects a second access of the UE to the UPF via an EPC. The UPF receives 504, from a data network, a data packet associated with the PFCP session of the MA-PDU session and determines 506 which of the 5GC access path or the EPC access path is to be used to transmit the data packet to the UE. When the 5GC access path is to be used, the UPF inserts 508 5GC-specific information in a header associated with the data packet and transmits the data packet, with the 5GC-specific information, via the 5GC access path. When the EPC access path is to be used, the UPF transmits 510 the data packet via the EPC access path, wherein the header associated with the data packet transmitted via the EPC access path does not include the 5GC-specific information.

Description

Comment NOTE 1: This parameter is only used for interworking with EPC.

[00121] In another example, the QER may include a new attribute QFI marking flag that is set when one access is connected to an EPC and the other access is connected only to a 5GC. In this example, the flag, when set, instructs the UPF to insert the QFI value only in headers associated with DL data packets that are to be sent on an access connected to the 5GC, i.e., the 5GC access path, which may be determined as described previously with reference to 506 of FIG. 5. 10

[00122] An example of such QER. is shown below, in which an additional new attribute, "QFI marking for 5GC access only" flag, not included in conventional QERs is shown bolded and underlined: Attribute Description Comment N4 Session ID Identifies the N4 session associated to this QER Rule ID Unique identifier to identify this information. QoS Enforcement Rule correlation ID (NOTE 1) An identity allowing the UP function to correlate multiple Sessions for the same UE and APN. Is used to correlate QoS Enforcement Rules for APN-AMBR enforcement. Gate status UL / DL Instructs the UP function to let the flow pass or to block the flow. Values are: open, close, close after measurement report (for termination action "discard"). Maximum bitrate The uplink / downlink maximum bitrate to be enforced for the packets. This field may e.g. contain any one of: - APN-AMBR (for a QER that is referenced by all relevant Packet Detection Rules of all PDN Connections to an APN) (NOTE 1). Session-AMBR (for a QER that is referenced by all relevant Packet Detection Rules of the PDU Session) QoS Flow MBR (for a QER that is referenced by all Packet Detection Rules of a QoS Flow) - SDF MBR (for a QER that is referenced by the uplink / downlink Packet Detection Rule of a SDF) Bearer MBR (for a QER that is referenced by all relevant Packet Detection Rules of a bearer) (NOTE 1). Guaranteed bitrate The uplink / downlink guaranteed bitrate authorized for the packets. This field contains: QoS Flow GBR (for a QER that is referenced by all Attribute Description Comment Packet Detection Rules of a QoS Flow) - Bearer GBR (for a QER that is referenced by all relevant Packet Detection Rules of a bearer) (NOTE 1). Averaging window The time duration over which the Maximum and Guaranteed bitrate shall be calculated. This is for counting the packets received during the time duration. Down-link flow level marking Flow level packet marking in the downlink. For UPF, this is for controlling the setting of the RQI in the encapsulation header as described in clause 5.7.5.3. QoS Flow ID QoS Flow ID to be inserted by the UPF. The UPF inserts the QFI value in the tunnel header of outgoing packets. If Conditional QFI marking applies, the UPF does so only if the condition expressed to insert the QFI is satisfied. "QFI marking for 5GC access only" flag This IE shall be set to 1 for an N4 Session related with ATSSS between an access connected to EPC and an access connected to 5GC. This may be present otherwise. When set to 1, this instructs the UPF to insert the QFI value only for an access connected to 5GC. Paging Policy Indicator Indicates the PPI value the UPF is required to insert in outgoing packets (see clause 5.4.3.2). PPI applies only for DL traffic. The UPF inserts the PPI in the outer header of outgoing PDU. Packet rate (NOTE 1) Number of packets per time interval to be enforced. This field contains any one of: downlink packet rate for Serving PLMN Rate Control (the QER is referenced by all PDRs of the UE belonging to PDN connections using CloT EPS Optimisations as described in TS 23.401

[26] ). uplink / downlink packet rate for APN Rate Control (the QER is referenced by all PDRs of the UE belonging to PDN connections to the same APN using CloT EPS Optimisations as described in TS 23.401

[26] ). End of Data Burst Marking Indication Indicates to the UPF to provide an End of Data Burst indication of the last PDU of a Data burst to the NG-RAN over GTP-U NG-RAN can configure UE power management schemes like connected mode DRX when UPF provides an indication of the End of Data Burst, see clause 5.37.8.3. PDU Set Information marking Indicator Indicates the UPF to insert PDU Set Information related to packets belonging to a PDU Set into GTP-U header. UPF identifies PDU Sets in DL traffic and forwards PDU Set related information of each PDU to the NG-RAN over GTP-U, as described in clause 5.37.5. NOTE 1: This parameter is only used for interworking with EPC.

[00123] Although the above QERs examples include an attribute related to conditional marking for the QFI only, in practice this modification could encompass attributes instructing the UPF to perform such condition marking related to any 5GC-specific information in addition to, or alternative to, conditional QFI marking such as, for example, conditional PPI and / or RQI marking as well, or conditional insertion of the GTP-ll session container header generally in a container that includes the DL data packet as payload, as described previously.

[00124] In yet another example, the MAR received from the SMF includes access specific QER ID(s), i.e. enabling the MAR to associated each access, i.e., each of the 3GPP and non-3GPP accesses, with access specific QERs, i.e. QER(s) specific to the 3GPP access and another QER(s) specific to the non-3GPP access of a MAR, where the QERs of an access connected to the 5GC requires the inclusion of 5GC-specific information such as QFI, i.e. for DL data packets to be transmitted on the 5GC access path, and where no QER or QER(s) not requiring the inclusion of 5GC-specific information are applied for the access connected to the EPC, i.e. for DL data packets to be transmitted on the EPC access path.

[00125] In this example, one set of QERs are applied to data packets to be sent along the 5GC access path, which instruct the UPF to insert the 5GC-specific information in a header associated with the data packet, such as a PDU session container header of a PDU session container that includes the data packet, and another set of QERs (or no QER) are applied to data packets to be sent along the EPC access path, which do not instruct the UPF to insert the 5GC-specific information in a header associated with the data packet, such as a PDU session container header of a PDU session container that includes the data packet. The SMF may set a QER identifier (QER ID) for each of the separate sets of QER, and the MAR instructs the UPF, using the QER ID, which set of QER to apply to a data packet based on which of the 5GC / EPC access paths is to be used to transmit the data packet, which may be determined as described previously at 506 of FIG. 5.

[00126] In some examples, the PDRs of the PFCP session may include a third set of common QERs that are applied to all data packets associated with the PFCP session regardless of which of the 5GC / EPC access paths they are to be sent on. These common QERs may include, for example, QER IEs that are not related to including the 5GC-specific information in a header associated with the data packet.

[00127] Referring to FIG. 6, and schematic diagram illustrating how a UPF 600 may determine which QERs to use is shown based on a PFCP model that includes access specific QERs. The example UPF 600 may include UPF functionality similar to any of the UPF functionality included in the UPFs previously described such as, for example, the UPF functionality included in UPF+PGW-U 310 and 410 of the example networks 300 and 400 previously described with reference to FIGS. 3 and 4.

[00128] A data packet is received at the UPF 600, and a PDR 602 associated with a PFCP session for the data packet is determined. The PDR may be received at the UPF 600 from an SMF (not shown) that establishes or modifies the PFCP session. This determination may be performed similar to the determination described previously with reference to FIG. 2 and is not further described here. The PDR 602 has a MAR 604 for the PFCP session.

[00129] The MAR 604 causes the UPF 600, when the access path to be used for transmitting the data packet is determined to be the 5GC access path, to apply a first QER 1 606 to the data packet, in addition to the FAR 1 608 that are applied to that access, i.e., 3GPP or non-3GPP. The QER 1 606 instructs the UPF 600 to include 5GC-specific information in a header associated with the data packet, such as a PDU session container header of a PDU session container that includes the data packet, prior to transmitting the data packet, i.e., the PDU session container that includes the data packet, out along the 5GC access path.

[00130] The MAR 604 causes the UPF 600, when the access path to be used for transmitting the data packet is determined to be the EPC access path, to apply a second QER 2 610 is applied to the data packet, in addition to the FAR 2 612 that are applied to that access, i.e., non-3GPP or 3GPP. The QER 2 610 does not include instructions for the UPF 600 to insert 5GC-specific information into a header associated with the data packet prior to sending the data packet out along the EPC access path. In other examples, no QER 2 610 may be included, 5 and the MAR 604 causes the UPF 600 not to apply any specific QER to the DL data packet that is to be transmitted on the EPC access path.

[00131] As described previously, the PDR 602 may optionally include common QER 3 614 that are applied by the UPF 600 to the data packet regardless of which access path that data packet is to be transmitted on. 10

[00132] In order to establish the PFCP session as described above and illustrated in FIG. 6, the existing forward action information for the outgoing tunnels associated with the 3GPP access and the non-3GPP access, which enable creation of separate FARs for each outgoing tunnel, may be utilized. A new QER ID information element may be included in the forward action information for the 15 outgoing tunnel associated with each of the 3GPP and non-3GPP accesses.

[00133] The forwarding action information for each of the 3GPP and non-3GPP access that exists in the Create MAR IE within a PFCP session establishment request are shown below, bolded for reference: Octet 1 and 2 Create MAR IE Type = 165 (decimal) Octets 3 and 4 Length = n Information elements P Condition / Comment Appl. IE Type Sxa Sxb Sxc N4 N4mb MAR ID M This IE shall uniquely identify the MAR among all the MARs configured for that PFCP session. - - - X - MAR ID Steering Functionality M This IE shall be present to indicate the applicable traffic steering functionality. - - - X - Steering Functionality Steering Mode M This IE shall be present to indicate the steering mode. - - - X - Steering Mode 3GPP Access Forwarding Action Information C This IE shall be present to provision 3GPP access specific forwarding action information if the UE is registered for 3GPP access, except when steering mode is set to "Active-Standby", Non-3GPP access is the active access and 3GPP access is not used as Standby access. In the latter case, this IE may be present. (NOTE) X 3GPP Access Forwarding Action Information Octet 1 and 2 Create MAR IE Type = 165 (decimal) Octets 3 and 4 Length = n Information elements P Condition / Comment Appl. IE Type Sxa Sxb Sxc N4 N4mb Non-3GPP Access Forwarding Action Information C This IE shall be present to provision non-3GPP access specific forwarding action information if the UE is registered for non-3GPP access, except when steering mode is set to "Active-Standby", 3GPP access is the active access and Non-3GPP access is not used as Standby access. In the latter case, this IE may be present. (NOTE 1) X Non-3GPP Access Forwarding Action Information Threshold Values C This IE shall be present if the steering mode is "Load Balancing" with fixed split percentages or "Prioritybased" and if available. This IE may also be present if the steering mode is "Redundant". When present, this IE shall contain the RTT and / or a Packet Loss Rate. If the Steering Mode is Redundant, either a (maximum) RTT or a (maximum) Packet Loss Rate may be provided, but not both. (NOTE 2) X Thresholds Steering Mode Indicator c This IE shall be included if at least one of the flags is set to "1": - ALBI (Autonomous Load Balancing Indicator): this flag shall be set to "1" if the SMF allows the UPF to apply autonomous load-balance when the Steering Mode is Load-Balancing; UEAI (UE Assistance Indicator): this flag shall be set to "1" if the SMF allows UE assistant load-balance when the Steering Mode is Load-Balancing. (NOTE 2) X Steering Mode Indicator Transport Mode c This IE shall be present to indicate the transport mode of the MPQUIC functionality, if the Steering Functionality is set to the MPQUIC functionality. In all other cases, this IE shall be absent. X Transport Mode NOTE 1: For the "Active-Standby" steering mode, if the network determines to not define a Standby access (as specified in clause 5.32.8 of 3GPP TS 23.501

[28] ), the SMF shall either set the Priority IE within (Non-)3GPP Access Forwarding Action Information IE to the value "No Standby" or not include the (Non-)3GPP Access Forwarding Action Information IE for that access not defined as Standby access. NOTE 2: The Threshold Values IE and the Steering Mode Indicator IE shall not be present together.

[00134] The forwarding action information in the create MAR. IE for both the 3GPP access and the non-3GPP access includes a QER ID which uniquely identifies the QER to be used among all of the QERs configured for the PFCP session, and enables the SMF to establish separate QoS related instructions for 5 different FARs such that the QERs that are applied to DL data packets transmitted on the 5GC access path have the 5GC-specific information inserted into a header associated with the DL data packets. Examples of the Access Forwarding Action Information IE in the Create MAR. IE for 3GPP and non-3PGG are included below, with the new "QED ID" information element shown in bolding and underlining for emphasis: Octet 1 and 2 3GPP Access Forwarding Action Information 1 IE Type = 166 (decimal) Octets 3 and 4 Length = n Information elements P Condition / Comment Appl. IE Type Sxa Sxb Sxc N4 N4mb FAR ID M This IE shall uniquely identify the FAR among all the FARs configured for this PFCP session. - - - X - FAR ID Weight C This IE shall be present if steering mode is set to "Load Balancing" to identify the weight of the FAR. (NOTE1) X Weight Priority C This IE shall be present if the steering mode is set to "Active-Standby" or "Priority-based". This IE may be present if the steering mode is set to "Redundant". (NOTE 2) X Priority URR ID C This IE shall uniquely identify the URR among all the URRs configured for the PFCP session. This enables the SMF to request separate usage reports for different FARs (i.e. different accesses) (NOTE 3) Several lEs within the same IE type may be present to represent a list of URRs to be associated to the FAR. X URR ID QERID c This IE shall uniquely identify the QER among all the QERs configured for the PFCP session. This X QERID enables the SMF to reguest separate QoS related instructions for different FARs (i.e. different accesses), e.g. to reguest the inclusion of QFI, PPI or RQI only for the 5GC access for a MA PDU session with a 5GC access and an EPC access. RAT Type 0 This IE may be present to provide the UP Function the current RAT Type for the DL FAR for statistics purpose. - - - X - RAT Type NOTE 1: The weights for all FARs included in both 3GPP Access Forwarding Action Information and Non 3GPP Access Forwarding Action Information need to sum upto 100. If the autonomous load balance operation is allowed, the Weights shall be treated as the default percentages. NOTE 2: The Priority value shall be set to "Active", "Standby" or "No Standby" if the Steering Mode is set to "Active-Standby". The Priority value shall be set to "High" or "Low" if the Steering Mode is set to "Priority-based". The Priority value shall be set to "Primary" or "Secondary" if the Steering Mode is set to "Redundant" and if the Priority IE is present. The 3GPP Access Forwarding Action Information and Non 3GPP Access Forwarding Action Information shall set different values; for the Redundant Steering Mode, this requirement shall apply only if the Priority IE is present. NOTE 3: One or more URRs may still be provisioned in the Create PDR IE when an MAR ID is present, while the URR(s) provisioned in this IE shall present a different set of URR(s) to request separate usage reports. Octet 1 and 2 Non-3GPP Access Forwarding Action Information IE Type = 167 (decimal) Octets 3 and 4 Length = n Information elements P Condition / Comment Appl. IE Type Sxa Sxb Sxc N4 N4mb FAR ID M This IE shall uniquely identify the FAR among all the FARs configured for this PFCP session. - - - X - FARID Weight C This IE shall be present if steering mode is set to "Load Balancing" to identify the weight of the FAR. - - - X - Weight Octet 1 and 2 Non-3GPP Access Forwarding Action Information IE Type = 167 (decimal) Octets 3 and 4 Length = n Information elements P Condition 1 Comment Appl. IE Type Sxa Sxb Sxc N4 N4mb (NOTE1) Priority C This IE shall be present if the steering mode is set to "Active-Standby" or "Priority-based". This IE may be present if the steering mode is set to "Redundant". (NOTE 2) - - - X - Priority URR ID C This IE shall uniquely identify the URR among all the URRs configured for the PFCP session. This enables the SMF to request separate usage reports for different FARs (i.e. different accesses) (NOTE 3) Several lEs within the same IE type may be present to represent a list of URRs to be associated to the FAR. X URR ID QER ID c This IE shall uniquely identify the QER among all the QERs configured for the PFCP session. This X QER ID enables the SMF to reguest separate QoS related instructions for different FARs (i.e. different accesses), e.g. to reguest the inclusion of QFI, PPI or RQI only for the 5GC access for a MA PDU session with a 5GC access and an EPC access. RAT Type 0 This IE may be present to provide the UP Function the current RAT Type for the DL FAR for statistics purpose. - - - X - RAT Type NOTE 1: The weights for all FARs included in both 3GPP Access Forwarding Action Information and Non 3GPP Access Forwarding Action Information need to sum upto 100. If the autonomous load balance operation is allowed, the Weights shall be treated as the default percentages. NOTE 2: The Priority value shall be set to "Active", "Standby" or "No Standby" if the Steering Mode is set to "Active-Standby". The Priority value shall be set to "High" or "Low" if the Steering Mode is set to "Priority-based". The Priority value shall be set to "Primary" or "Secondary" if the Steering Mode is set to "Redundant" and if the Priority IE is present. The 3GPP Access Forwarding Action Information and Non 3GPP Access Forwarding Action Information shall set different values; for the Redundant Steering Mode, this requirement shall apply only if the Priority IE is present. NOTE 3: One or more URRs may still be provisioned in the Create PDR IE when an MAR ID is present, while the URR(s) provisioned in this IE shall present a different set of URR(s) to request separate usage reports.

[00135] In this example, the process used by the SMF to establish or modify a conventional PFCP session with the UPF, as set out in the current 3GPP standard for 5GC, may be used. Only the contents to the QER, FAR, and possibly MAR sent from the SMF to the UPF are changed. 5

[00136] In addition to using separate QERs for each of the 3GPP and non-3GPP accesses to implement conditional 5GC-specific information being inserted into a header associated with the data packets, separate QERs may be used more generally to support specific QoS enforcement that is different for each of the 3GPP and non-3GPP access. For example, if the maximum bit rate (MBR) that 10 can be supported on one access is much lower than the MBR that can be supported by another access, this can be accounted for in different QERs that are specific to each of the accesses.

[00137] In another embodiment, the UPF may be instructed by the PDRs received from the SMF to remove any 5GC-specific information that is included in a header associated with data packet, such as a PDU session container header of 5 a PDU session container that includes the data packet, before that data packet is transmitted on an EPC access path, rather than instructing the UPF to conditionally insert the 5GC-specific information only into the headers associated with data packets that are to be transmitted on the 5GC access path, and not into the headers associated with data packets that are to be transmitted on the 10 EPC access path, as in previously-described embodiments.

[00138] This embodiment may be implemented by modifying the FAR. associated with the EPC access path to include an information element that causes the UPF to remove 5GC-specific information included in a header associated with DL data packets to be transmitted on the EPC access path. 15

[00139] For example, the FAR. for the outgoing tunnel of the UPF associated with the EPC access path may include an additional indication (e.g., a flag) that indicates that any QFI is to be removed. In another example, the FAR. for the outgoing tunnel of the UPF associated with the EPC access path may include a new "outer header removal" information element comprising instructions to the 20 UPF that the QFI is to be removed, as shown in the below example FAR in which the "outer header removal" information element is shown in bolding and underlining for emphasis: Octet 1 and 2 Forwarding Parameters IE Type = 4 (decimal) Octets 3 ai id 4^"- Length - n Information elements P Condition 1 Comment Appl. IE Type Sx a Sx b Sx c N4 N4 mb Destination Interface M This IE shall identify the destination interface of the outgoing packet. X X X X - Destination Interface Network Instance 0 When present, this IE shall identify the Network instance towards which to send the outgoing packet. See NOTE 1. X X X X - Network Instance Redirect Information C This IE shall be present if the UP function is required to enforce traffic redirection towards a redirect destination provided by the CP function. - X X X - Redirect Information Octet 1 and 2 Forwarding Parameters IE Type = 4 (decimal) Octets 3 and 4 Length = n Information elements p Condition / Comment Appl. IE Type Sx a Sx b Sx c N4 N4 mb Outer Header Creation c This IE shall be present if the UP function is required to add one or more outer header(s) to the outgoing packet. If present, it shall contain the F-TEID of the remote GTP-U peer when adding a GTP-U / UDP / IP header, or the Destination IP address and / or Port Number when adding a UDP / IP header or an IP header or the C-TAG / S-TAG (for 5GC). See NOTE 2. X X X Outer Header Creation Transport Level Marking c This IE shall be present if the UP function is required to mark the IP header with the DSCP marking as defined by IETF RFC 2474

[22] , When present for EPC, it shall contain the value of the DSCP in the TOS / Traffic Class field set based on the QCI, and optionally the ARP priority level, of the associated EPS bearer, as described in clause 5.10 of 3GPP TS 23.214 [2], When present for 5GC, it shall contain the value of the DSCP in the TOS / Traffic Class field set based on the 5QI, the Priority Level (if explicitly signalled), and optionally the ARP priority level, of the associated QoS flow, as described in clause 5.8.2.7 of 3GPP TS 23.501

[28] , X X X Transport Level Marking Forwarding Policy c This IE shall be present if a specific forwarding policy is required to be applied to the packets. It shall be present if the Destination Interface IE is set to SGi-U\N 1N6-LAN. It may be present if the Destination Interface is set to Core, Access, or CP-Function. See NOTE 2. When present, it shall contain an Identifier of the Forwarding Policy locally configured in the UP function. X X X Forwarding Policy Metadata 0 This IE may be included to provide the metadata by the AF which the UPF needs to add to traffic sent over a Service Function Chain. How the UPF transforms the metadata into actual information sent with the traffic (e.g., in the encapsulation header) is based on local policies related with the Forwarding Policy and not specified. X Metadata Header Enrichment 0 This IE may be present if the UP function indicated support of Header Enrichment of UL traffic. When present, it shall contain information for header enrichment. - X X X - Header Enrichment Linked Traffic Endpoint ID c This IE may be present, if it is available and the UP function indicated support of the PDI optimisation feature, (see clause 8.2.25). When present, it shall identify the Traffic Endpoint ID allocated for this PFCP session to receive the traffic in the reverse direction (see clause 5.2.3.1). X X X Traffic Endpoint ID Proxying c This IE shall be present if proxying is to be performed by the UP function. When present, this IE shall contain the information that the UPF shall respond to Address Resolution Protocol and / or IPv6 Neighbour Solicitation based on the local cache information for the Ethernet PDUs. X Proxying Destination Interface Type 0 This IE may be present to indicate the 3GPP interface type of the destination interface, if required by X X - X - 3GPP Interface Type Octet 1 and 2 Forwarding Parameters IE Type = 4 (decimal) Octets 3 and 4 Length = n Information elements p Condition / Comment Appl. IE Type Sx a Sx b Sx c N4 N4 mb functionalities in the UP Function, e.g. for performance measurements. Data Network Access Identifier c This IE shall be present over N16a to link the UL FAR in an UL CL or BP towards a specific local PSA, if more than one local PSA has been inserted by an l-SMF. It may be present over N16a otherwise. This IE shall not be sent over N4. When present, it shall be set to the DNAI associated to the local PSA towards which the UL traffic shall be forwarded. Data Network Access Identifier IP Address and Port Number Replacement c This IE shall be present if the UP function indicated support of replacing the source and destination IP address and Port Number of an (inner) IP packet, and if the source or destination IP address and / or port number of the (Inner) IP packet shall be modified, e.g. for Edge Relocation using EAS IP address and Port number Replacement (see clause 5.33.3). This IE shall also be present if the destination IP address and / or port number of the (Inner) IP packet shall be modified, e.g. for EAS Discovery procedure with Local DNS Server / Resolver using Local DNS Server / Resolver IP address and Port number Replacement (see clause 5.33.4). (NOTE 3) X IP Address and Port Number Replacement Outer Header c This IE shall be present for FAR to an EPC tunnel. X X - X X Outer Header Removal Removal that may be used by a MAR for ATSSS between an access connected to EPC and an access connected to 5GC, to request the UPF to remove anv QFI from the DL packets.

[00140] Although the example FAR included above includes an information element directed to instructing the UPF to remove the QFI only, in practice the FAR could include information elements instructing the UPF to remove any 5GC- 5 specific information in addition to, or alternative to, the QFI such as, for example, removing PPI or RQI as well, or, more generally, instructing the UPF to remove the GTP-U session container header of a GTP-U session container that includes the DL data packet.

[00141] In this embodiment, the UPF may be instructed, or pre-configured, to 10 insert 5GC-specific information into the headers associated with all data packets, regardless of the access path that the data packet is to be transmitted on, in accordance with conventional QERs, but for those data packets to be transmitted on the EPC access path, the 5GC-specific information is removed from the header by the UPF prior to transmitting the data packet in accordance with, for example, the FAR associated with the EPC access path.

[00142] Referring to FIG. 7, a schematic diagram illustrating various physical and logical components of an exemplary apparatus 700 for a communication network in accordance with an embodiment is shown. Although an example embodiment of the apparatus 700 is shown and discussed below, other embodiments may be used to implement examples disclosed herein, which may include components different from those shown. Although FIG. 7 shows a single instance of each component of the apparatus 700, there may be multiple instances of each component shown.

[00143] The apparatus 700 includes one or more processors 702, such as a central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a dedicated logic circuitry, a graphics processing unit (GPU), a tensor processing unit, a neural processing unit, a dedicated artificial intelligence processing unit, a hardware accelerator, or combinations thereof. The one or more processors 702 may collectively be referred to as a processor 702.

[00144] The apparatus 700 also includes one or more memories 104 (collectively referred to as "memory 704"), which may include a volatile or nonvolatile memory (e.g., a flash memory, a random-access memory (RAM), and / or a read-only memory (ROM)). The non-transitory memory 704 may store instructions for execution by the processor 702. In some embodiments, instructions 706 of a UPF and / or a SMF described herein may be stored in the memory 704, and the instructions 706 may be executed by the processor 102 to perform the actions or operations of the methods described herein. The memory 704 may include other instructions for execution by the processor 702, such as instructions of other network functions of a communication network, such as those described above.

[00145] The apparatus 700 may also include one or more network interfaces 708 for connecting to a network, such as a data network, or other apparatuses of the core network or the access networks described herein.

[00146] In some examples, the apparatus 700 may also include one or more electronic storage units (not shown), such as a solid state drive, a hard disk drive, a magnetic disk drive and / or an optical disk drive. In some examples, one or more datasets and / or modules may be provided by an external memory (e.g., an external drive in wired or wireless communication with the computing system 100) or may be provided by a transitory or non-transitory computer-readable medium. Examples of non-transitory computer readable media include a RAM, a ROM, an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a CD-ROM, or other portable memory storage. The storage units and / or external memory may be used in conjunction with memory 704 to implement data storage, retrieval, and caching functions of the apparatus 700.

[00147] The components of the apparatus 700 may communicate with each other via a bus. In some embodiments, the apparatus 700 may be a processing system implementing functionality of the UPF and / or the SMF described herein. In some embodiments, the apparatus 700 may be distributed computing system and may include multiple computing devices in communication with each other over a data network, as well as optionally one or more additional components. The various operations described herein may be performed by different computing devices of a distributed computing system in some embodiments. In some embodiments, the apparatus 700 a cloud computing system or may be a virtual machine provided by a cloud computing system.

[00148] Embodiments of the present invention including functions, processes, and operations, may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and / or hardware may reside on memory, or any computer media. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this application, a "memory" or "computer-readable medium" may be any non-transitory media or means that contains, stores, communicates, propagates or transports the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[00149] Reference to, where relevant, "computer-readable medium", "computer program product", "tangibly embodied computer program" etc., or a "processor" or "processing circuitry" etc. should be understood to encompass not only computers having differing architectures such as single / multi-processor architectures and sequencers / parallel architectures, but also specialized circuits such as field programmable gate arrays FPGA, application specify circuits ASIC, signal processing devices / apparatus and other devices / apparatus. References to computer program, instructions, code etc. should be understood to express software for a programmable processor firmware such as the programmable content of a hardware device / apparatus as instructions for a processor or configured or configuration settings for a fixed function device / apparatus, gate array, programmable logic device / apparatus, etc.

[00150] As used in the present disclosure, the term "circuitry", for example in the hardware processing circuitry that may be used to implement the UPF or the SMF in accordance with certain embodiments of the present disclosure, may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (iii) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in the present disclosure, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[00151] The functions, processes, and operations described herein may be performed in a different order, or may be performed concurrently with each other, or a combination thereof. Furthermore, one or more of the functions, processes, and operations may be optional or may be combined. It will be appreciated that the flow diagram shown in FIG. 5 and the various embodiments described with reference to FIG. 5, are examples only. Various operations and processes depicted therein may be omitted, may be reordered, may be combined, ora combination of reordered and combined.

[00152] Advantageously, the UPF transmitting data packets on a 5GC access pathway in which 5GC-specific information is inserted into headers associated those data packets and transmitting data packets on an EPC access pathway with no 5GC-specific information included in a header associated with those data packets enables MA-PDll connectivity services when one of a 3GPP access and a non-3GPP access is connected to a 5GC and the other of the 3GPP access and the non-3GPP access is connected to an EPC.

[00153] The scope of the claims should not be limited by the preferred embodiments set forth in the examples but should be given the broadest interpretation consistent with the description as a whole.

Claims

1. A method for a user plane function (UPF) to provide data to a user equipment (UE), the method comprising:receiving, from a session management function (SMF), rules associated with a packet forwarding control protocol (PFCP) session of a multi-access protocol data unit (MA-PDU) session in which a 5G core (5GC) access path connects a first access of the UE to the UPF via a 5GC and an evolved packet core (EPC) access path connects a second access of the UE to the UPF via an EPC;receiving a data packet from a data network, the data packet associated with the PFCP session of the MA-PDU session;determining which the 5GC access path or the EPC access path is to be used to transmit the data packet to the UE;when the 5GC access path is to be used to transmit the data packet, inserting 5GC-specific information in a header associated with the data packet and transmitting the data packet, with the 5GC-specific information, via the 5GC access path; andwhen the EPC access path is to be used to transmit the data packet, transmitting the data packet via the EPC access path, wherein the header associated with the data packet transmitted via the EPC access path does not include the 5GC-specific information.

2. The method according to claim 1, wherein the rules received from the SMF include a forwarding action rule (FAR) having a forwarding parameter, wherein the forwarding parameter is:a destination interface type that indicates an interface of the UPF to be used to transmit the data packet, the indicated interface being associated with either the 5GC access path or the EPC access path; ora system type that indicates whether the access path to be used to transmit the data packet travels through the EPC or only travels through the 5GC; andwherein determining which one of the 5GC access path and the EPC access path is to be used to transmit the data packet is performed based on the forwarding parameter of the FAR.

3. The method according to claim 1 or claim 2, wherein the rules received from the SMF include a conditional rule included in quality of service enforcement rule (QER) that instructs the UPF to insert 5GC-specific information in a header associated with the data packet only in response to determining that the data packet is to be transmitted on the 5GC access path.

4. The method according to claim 1 or 2, wherein the rules received by the UPF from the SMF include:a first QER that apply to data packets to be transmitted on the 5GC access path and that instruct the UPF to insert the 5GC-specific information into the header associated with the data packet, anda second QER that apply to data packets to be transmitted on the EPC access path and that instruct the UPF not to insert the 5GC-specific information into the header associated with the data packet and, wherein:inserting the 5GC-specific information in the header associated with the data packet and transmitting the data packet with the 5GC-specific information via the 5GC access path comprises applying the first QER to the data packet prior to transmitting the data packet on the 5GC access path; andtransmitting the data packet via the EPC access path, wherein the header associated withO the data packet transmitted via the EPC access path does not include the 5GC-specific information, comprises applying the secondQER to the data packet prior to transmitting the data packet on the EPC access path.

5. The method according to claim 1 or 2, wherein:receiving the rules from the SMF comprises receiving a forwarding action rule (FAR) associated with the EPC access path instructing the UPF to remove any 5GC-specific information in the header associated with any data packet to be transmitted on the EPC access path; andtransmitting the data packet via the EPC access path, wherein the header associated with the data packet transmitted via the EPC access path does not include the 5GC-specific information, comprises applying the FAR by removing the 5GC-specific information from the header associated with the data packet prior to transmitting the data packet.

6. The method according to any one of claims 1 to 5, wherein the 5GC-specific information associated with the data packet includes at least one of a quality of service flow identifier (QFI), a reflective quality of service indicator (RQI), and a paging policy indicator (PPI), and the header associated the data packet is a GTP-U protocol data unit (PDU) session container header of a GTP-U session container that includes the data packet.

7. A method for a session management function (SMF), the method comprising:transmitting to a user plane function (UPF) rules associated with a packet forwarding control protocol (PFCP) session of the MA-PDU session in which a 5G core (5GC) access path connects a first access of a UE to the UPF via a 5GC and an evolved packet core (EPC) access path connects a second access of the UE to the UPF via an EPC;wherein, for a data packet associated with the PFCP session of the MA-PDU session that is received at the UPF from a data network, the rules instruct the UPF to:determine which the 5GC access path or the EPC access path is to be used to transmit the data packet to the UE;when the data packet is to be transmitted on the 5GC access path, insert 5GC-specific information in a header associated with the data packet and transmit the data packet, with the 5GC-specific information via the 5GC access path; andwhen the data packet is to be transmitted on the EPC access path, transmit the data packet via the EPC access path, wherein the header associated with the data packet transmitted via the EPC access path does not include the 5GC-specific information.

8. The method according to claim 7, wherein the rules include a forwarding action rule (FAR.) having a forwarding parameter, wherein the forwarding parameter is:a destination interface type that indicates an interface of the UPF to be used to transmit the data packet, the indicated interface being associated with either the 5GC access path or the EPC access path; ora system type that indicates whether the access path to be used to transmit the data packet travels through the EPC or only travels through the 5GC; andwherein the rules instructing the UPF to determine which one of the 5GC access path and the EPC access path is to be used to transmit the data packet comprise the rules instructing the UPF to perform the determining based on the forwarding parameter of the FAR..

9. The method according to claim 7 or 8, wherein the rules include a conditional rule included in a quality of service enforcement rule (QER) that instructs the UPF to insert 5GC-specific information only when the data packet is to be transmitted on the 5GC access path is satisfied.

10. The method according to claim 7 or 8, wherein the rules include:a first quality of service enforcement rule (QER) that applies only to data packets to be transmitted on the 5GC access path and that instructs the UPF to insert the 5GC-specific information into the header associated with the data packet, anda second QER that applies only to data packets to be transmitted on the EPC access path and that instructs the UPF not to insert the 5GC-specific information into the header associated with the data packet, or to remove any 5GC-specific information included in the header associated with the data packet.

11. The method according to claim 7 or 8, wherein:the rules comprise a forwarding action rule (FAR) associated with the EPC access path that instructs the UPF to remove any 5GC-specific information in the header associated with any data packet to be transmitted on the EPC access path.

12. The method according to any one of claims 7 to 11, wherein the 5GC-specific information associated with the data packet includes at least one of a quality of service flow identifier (QFI), a reflective quality of service indicator (RQI), and a paging policy indicator (PPI), and the header associated the data packet is a GTP-U protocol data unit (PDU) session container header of a GTP-U session container that includes the data packet.

13. An apparatus comprising:at least one processor;at least one memory storing instructions of a user plane function (UPF), wherein when the instructions are executed by the at least one processor, cause the apparatus to perform the method of any of claims 1 to 6.

14. A computer-readable medium storing instructions of a user plane function (UPF), wherein when the instructions are executed by at least one processor of an apparatus, cause the apparatus to perform the method of any of claims 1 to 6.

15. An apparatus comprising:at least one processor;at least one memory storing instructions of a session management function (SMF), wherein when the instructions are executed by at least one processor, cause the apparatus to perform the method of any of claims 7 to 12.

16. A computer-readable medium storing instructions of a session management function (SMF), wherein when the instructions are executed by at least one processor of an apparatus, cause the apparatus to perform the method of any of claims 7 to 12.58

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